1. Field of the Invention
This invention relates to an article for forming a metallic image thereon, and more particularly to a metallic image forming material capable of forming a high contrast image and suitable for producing line work and half-tone dots.
2. Description of the Prior Art
The conventional "chromium mask" produced by vacuum-depositing a Cr layer on a glass sheet surface and applying thereon a photosensitive resin layer is used for making the printed base plate of an integrated circuit by exposing and developing the "chromium mask" to form a solidified and etched resist of the resin layer and to remove the Cr deposited layer. Since the image forming material is metallic Cr, the formed image is strong but the Cr layer is scarcely etched. In addition, the Cr ion dissolved in the etching solution causes environmental pollution when discharged into the environment.
The image forming material used in the process described in Japanese Patent Application (O.P.I.) Nos. 65927/73 and 65928/73, is a vacuum-deposited layer of a Te containing composition. Te is not plentiful, is a precious resource and sometimes is toxic in nature.
One preferred metal for producing an image forming layer is Al, but Al is scarcely etched by usual etching compositions, thus a long etching time is required. Accordingly, the resist material must be durable for a long time against the attack of the etching solution so that the resist is not impaired, and in addition if etching is conducted for a long period the image obtained is disordered and not sharp.